bfd/elf32-sh-symbian.c

   1 /* Renesas / SuperH specific support for Symbian 32-bit ELF files
   2    Copyright 2004, 2005
   3    Free Software Foundation, Inc.
   4    Contributed by Red Hat
   5
   6    This file is part of BFD, the Binary File Descriptor library.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  21
  22 /* Stop elf32-sh.c from defining any target vectors.  */
  23 #define SH_TARGET_ALREADY_DEFINED
  24 #define sh_find_elf_flags           sh_symbian_find_elf_flags
  25 #define sh_elf_get_flags_from_mach  sh_symbian_elf_get_flags_from_mach
  26 #include "elf32-sh.c"
  27
  28
  29 //#define DEBUG 1
  30 #define DEBUG 0
  31
  32 #define DIRECTIVE_HEADER        "#<SYMEDIT>#\n"
  33 #define DIRECTIVE_IMPORT        "IMPORT "
  34 #define DIRECTIVE_EXPORT        "EXPORT "
  35 #define DIRECTIVE_AS            "AS "
  36
  37 /* Macro to advance 's' until either it reaches 'e' or the
  38    character pointed to by 's' is equal to 'c'.  If 'e' is
  39    reached and DEBUG is enabled then the error message 'm'
  40    is displayed.  */
  41 #define SKIP_UNTIL(s,e,c,m)                                     \
  42   do                                                            \
  43     {                                                           \
  44       while (s < e && *s != c)                                  \
  45         ++ s;                                                   \
  46       if (s >= e)                                               \
  47         {                                                       \
  48           if (DEBUG)                                            \
  49             fprintf (stderr, "Corrupt directive: %s\n", m);     \
  50           result = FALSE;                                       \
  51         }                                                       \
  52     }                                                           \
  53   while (0);                                                    \
  54   if (!result)                                                  \
  55      break;
  56
  57 /* Like SKIP_UNTIL except there are two terminator characters
  58    c1 and c2.  */
  59 #define SKIP_UNTIL2(s,e,c1,c2,m)                                \
  60   do                                                            \
  61     {                                                           \
  62       while (s < e && *s != c1 && *s != c2)                     \
  63         ++ s;                                                   \
  64       if (s >= e)                                               \
  65         {                                                       \
  66           if (DEBUG)                                            \
  67             fprintf (stderr, "Corrupt directive: %s\n", m);     \
  68           result = FALSE;                                       \
  69         }                                                       \
  70     }                                                           \
  71   while (0);                                                    \
  72   if (!result)                                                  \
  73      break;
  74
  75 /* Macro to advance 's' until either it reaches 'e' or the
  76    character pointed to by 's' is not equal to 'c'.  If 'e'
  77    is reached and DEBUG is enabled then the error message
  78    'm' is displayed.  */
  79 #define SKIP_WHILE(s,e,c,m)                                     \
  80   do                                                            \
  81     {                                                           \
  82       while (s < e && *s == c)                                  \
  83         ++ s;                                                   \
  84       if (s >= e)                                               \
  85         {                                                       \
  86           if (DEBUG)                                            \
  87             fprintf (stderr, "Corrupt directive: %s\n", m);     \
  88           result = FALSE;                                       \
  89         }                                                       \
  90     }                                                           \
  91   while (0);                                                    \
  92   if (!result)                                                  \
  93      break;
  94
  95
  96 typedef struct symbol_rename
  97 {
  98   struct symbol_rename *       next;
  99   char *                       current_name;
 100   char *                       new_name;
 101   struct elf_link_hash_entry * current_hash;
 102   unsigned long                new_symndx;
 103 }
 104 symbol_rename;
 105
 106 static symbol_rename * rename_list = NULL;
 107
 108 /* Accumulate a list of symbols to be renamed.  */
 109
 110 static bfd_boolean
 111 sh_symbian_import_as (struct bfd_link_info *info, bfd * abfd,
 112                       char * current_name, char * new_name)
 113 {
 114   struct elf_link_hash_entry * new_hash;
 115   symbol_rename * node;
 116
 117   if (DEBUG)
 118     fprintf (stderr, "IMPORT '%s' AS '%s'\n", current_name, new_name);
 119
 120   for (node = rename_list; node; node = node->next)
 121     if (strcmp (node->current_name, current_name) == 0)
 122       {
 123         if (strcmp (node->new_name, new_name) == 0)
 124           /* Already added to rename list.  */
 125           return TRUE;
 126
 127         bfd_set_error (bfd_error_invalid_operation);
 128         _bfd_error_handler (_("%B: IMPORT AS directive for %s conceals previous IMPORT AS"),
 129                             abfd, current_name);
 130         return FALSE;
 131       }
 132
 133   if ((node = bfd_malloc (sizeof * node)) == NULL)
 134     {
 135       if (DEBUG)
 136         fprintf (stderr, "IMPORT AS: No mem for new rename node\n");
 137       return FALSE;
 138     }
 139
 140   if ((node->current_name = bfd_malloc (strlen (current_name) + 1)) == NULL)
 141     {
 142       if (DEBUG)
 143         fprintf (stderr, "IMPORT AS: No mem for current name field in rename node\n");
 144       free (node);
 145       return FALSE;
 146     }
 147   else
 148     strcpy (node->current_name, current_name);
 149
 150   if ((node->new_name = bfd_malloc (strlen (new_name) + 1)) == NULL)
 151     {
 152       if (DEBUG)
 153         fprintf (stderr, "IMPORT AS: No mem for new name field in rename node\n");
 154       free (node->current_name);
 155       free (node);
 156       return FALSE;
 157     }
 158   else
 159     strcpy (node->new_name, new_name);
 160
 161   node->next = rename_list;
 162   node->current_hash = NULL;
 163   node->new_symndx = 0;
 164   rename_list = node;
 165
 166   new_hash = elf_link_hash_lookup (elf_hash_table (info), node->new_name, TRUE, FALSE, TRUE);
 167   bfd_elf_link_record_dynamic_symbol (info, new_hash);
 168   if (new_hash->root.type == bfd_link_hash_new)
 169     new_hash->root.type = bfd_link_hash_undefined;
 170
 171   return TRUE;
 172 }
 173
 174
 175 static bfd_boolean
 176 sh_symbian_import (bfd * abfd ATTRIBUTE_UNUSED, char * name)
 177 {
 178   if (DEBUG)
 179     fprintf (stderr, "IMPORT '%s'\n", name);
 180
 181   /* XXX: Generate an import somehow ?  */
 182
 183   return TRUE;
 184 }
 185
 186 static bfd_boolean
 187 sh_symbian_export (bfd * abfd ATTRIBUTE_UNUSED, char * name)
 188 {
 189   if (DEBUG)
 190     fprintf (stderr, "EXPORT '%s'\n", name);
 191
 192   /* XXX: Generate an export somehow ?  */
 193
 194   return TRUE;
 195 }
 196
 197 /* Process any magic embedded commands in the .directive. section.
 198    Returns TRUE upon sucecss, but if it fails it sets bfd_error and
 199    returns FALSE.  */
 200
 201 static bfd_boolean
 202 sh_symbian_process_embedded_commands (struct bfd_link_info *info, bfd * abfd,
 203                                       asection * sec, bfd_byte * contents)
 204 {
 205   char *s;
 206   char *e;
 207   bfd_boolean result = TRUE;
 208   bfd_size_type sz = sec->rawsize ? sec->rawsize : sec->size;
 209
 210   for (s = (char *) contents, e = s + sz; s < e;)
 211     {
 212       char * directive = s;
 213
 214       switch (*s)
 215         {
 216           /* I want to use "case DIRECTIVE_HEADER [0]:" here but gcc won't let me :-(  */
 217         case '#':
 218           if (strcmp (s, DIRECTIVE_HEADER))
 219             result = FALSE;
 220           else
 221             /* Just ignore the header.
 222                XXX: Strictly speaking we ought to check that the header
 223                is present and that it is the first thing in the file.  */
 224             s += strlen (DIRECTIVE_HEADER) + 1;
 225           break;
 226
 227         case 'I':
 228           if (strncmp (s, DIRECTIVE_IMPORT, strlen (DIRECTIVE_IMPORT)))
 229             result = FALSE;
 230           else
 231             {
 232               char * new_name;
 233               char * new_name_end;
 234               char   name_end_char;
 235
 236               /* Skip the IMPORT directive.  */
 237               s += strlen (DIRECTIVE_IMPORT);
 238
 239               new_name = s;
 240               /* Find the end of the new name.  */
 241               while (s < e && *s != ' ' && *s != '\n')
 242                 ++ s;
 243               if (s >= e)
 244                 {
 245                   /* We have reached the end of the .directive section
 246                      without encountering a string terminator.  This is
 247                      allowed for IMPORT directives.  */
 248                   new_name_end   = e - 1;
 249                   name_end_char  = * new_name_end;
 250                   * new_name_end = 0;
 251                   result = sh_symbian_import (abfd, new_name);
 252                   * new_name_end = name_end_char;
 253                   break;
 254                 }
 255
 256               /* Remember where the name ends.  */
 257               new_name_end = s;
 258               /* Skip any whitespace before the 'AS'.  */
 259               SKIP_WHILE (s, e, ' ', "IMPORT: Name just followed by spaces");
 260               /* Terminate the new name.  (Do this after skiping...)  */
 261               name_end_char = * new_name_end;
 262               * new_name_end = 0;
 263
 264               /* Check to see if 'AS '... is present.  If se we have an IMPORT AS
 265                  directive, otherwise we have an IMPORT directive.  */
 266               if (strncmp (s, DIRECTIVE_AS, strlen (DIRECTIVE_AS)))
 267                 {
 268                   /* Skip the new-line at the end of the name.  */
 269                   if (DEBUG && name_end_char != '\n')
 270                     fprintf (stderr, "IMPORT: No newline at end of directive\n");
 271                   else
 272                     s ++;
 273
 274                   result = sh_symbian_import (abfd, new_name);
 275
 276                   /* Skip past the NUL character.  */
 277                   if (* s ++ != 0)
 278                     {
 279                       if (DEBUG)
 280                         fprintf (stderr, "IMPORT: No NUL at end of directive\n");
 281                     }
 282                 }
 283               else
 284                 {
 285                   char * current_name;
 286                   char * current_name_end;
 287                   char   current_name_end_char;
 288
 289                   /* Skip the 'AS '.  */
 290                   s += strlen (DIRECTIVE_AS);
 291                   /* Skip any white space after the 'AS '.  */
 292                   SKIP_WHILE (s, e, ' ', "IMPORT AS: Nothing after AS");
 293                   current_name = s;
 294                   /* Find the end of the current name.  */
 295                   SKIP_UNTIL2 (s, e, ' ', '\n', "IMPORT AS: No newline at the end of the current name");
 296                   /* Skip (backwards) over spaces at the end of the current name.  */
 297                   current_name_end = s;
 298                   current_name_end_char = * current_name_end;
 299
 300                   SKIP_WHILE (s, e, ' ', "IMPORT AS: Current name just followed by spaces");
 301                   /* Skip past the newline character.  */
 302                   if (* s ++ != '\n')
 303                     if (DEBUG)
 304                       fprintf (stderr, "IMPORT AS: No newline at end of directive\n");
 305
 306                   /* Terminate the current name after having performed the skips.  */
 307                   * current_name_end = 0;
 308
 309                   result = sh_symbian_import_as (info, abfd, current_name, new_name);
 310
 311                   /* The next character should be a NUL.  */
 312                   if (* s != 0)
 313                     {
 314                       if (DEBUG)
 315                         fprintf (stderr, "IMPORT AS: Junk at end of directive\n");
 316                       result = FALSE;
 317                     }
 318                   s ++;
 319
 320                   * current_name_end = current_name_end_char;
 321                 }
 322
 323               /* Restore the characters we overwrote, since
 324                  the .directive section will be emitted.  */
 325               * new_name_end = name_end_char;
 326             }
 327           break;
 328
 329         case 'E':
 330           if (strncmp (s, DIRECTIVE_EXPORT, strlen (DIRECTIVE_EXPORT)))
 331             result = FALSE;
 332           else
 333             {
 334               char * name;
 335               char * name_end;
 336               char   name_end_char;
 337
 338               /* Skip the directive.  */
 339               s += strlen (DIRECTIVE_EXPORT);
 340               name = s;
 341               /* Find the end of the name to be exported.  */
 342               SKIP_UNTIL (s, e, '\n', "EXPORT: no newline at end of directive");
 343               /* Skip (backwards) over spaces at end of exported name.  */
 344               for (name_end = s; name_end[-1] == ' '; name_end --)
 345                 ;
 346               /* name_end now points at the first character after the
 347                  end of the exported name, so we can termiante it  */
 348               name_end_char = * name_end;
 349               * name_end = 0;
 350               /* Skip passed the newline character.  */
 351               s ++;
 352
 353               result = sh_symbian_export (abfd, name);
 354
 355               /* The next character should be a NUL.  */
 356               if (* s != 0)
 357                 {
 358                   if (DEBUG)
 359                     fprintf (stderr, "EXPORT: Junk at end of directive\n");
 360                   result = FALSE;
 361                 }
 362               s++;
 363
 364               /* Restore the character we deleted.  */
 365               * name_end = name_end_char;
 366             }
 367           break;
 368
 369         default:
 370           result = FALSE;
 371           break;
 372         }
 373
 374       if (! result)
 375         {
 376           if (DEBUG)
 377             fprintf (stderr, "offset into .directive section: %ld\n",
 378                      (long) (directive - (char *) contents));
 379
 380           bfd_set_error (bfd_error_invalid_operation);
 381           _bfd_error_handler (_("%B: Unrecognised .directive command: %s"),
 382                               abfd, directive);
 383           break;
 384         }
 385     }
 386
 387   return result;
 388 }
 389
 390
 391 /* Scan a bfd for a .directive section, and if found process it.
 392    Returns TRUE upon success, FALSE otherwise.  */
 393 bfd_boolean bfd_elf32_sh_symbian_process_directives (struct bfd_link_info *info, bfd * abfd);
 394
 395 bfd_boolean
 396 bfd_elf32_sh_symbian_process_directives (struct bfd_link_info *info, bfd * abfd)
 397 {
 398   bfd_boolean result = FALSE;
 399   bfd_byte *  contents;
 400   asection *  sec = bfd_get_section_by_name (abfd, ".directive");
 401   bfd_size_type sz;
 402
 403   if (!sec)
 404     return TRUE;
 405
 406   sz = sec->rawsize ? sec->rawsize : sec->size;
 407   contents = bfd_malloc (sz);
 408
 409   if (!contents)
 410     bfd_set_error (bfd_error_no_memory);
 411   else
 412     {
 413       if (bfd_get_section_contents (abfd, sec, contents, 0, sz))
 414         result = sh_symbian_process_embedded_commands (info, abfd, sec, contents);
 415       free (contents);
 416     }
 417
 418   return result;
 419 }
 420
 421 /* Intercept the normal sh_relocate_section() function
 422    and magle the relocs to allow for symbol renaming.  */
 423
 424 static bfd_boolean
 425 sh_symbian_relocate_section (bfd *                  output_bfd,
 426                              struct bfd_link_info * info,
 427                              bfd *                  input_bfd,
 428                              asection *             input_section,
 429                              bfd_byte *             contents,
 430                              Elf_Internal_Rela *    relocs,
 431                              Elf_Internal_Sym *     local_syms,
 432                              asection **            local_sections)
 433 {
 434   /* When performing a final link we implement the IMPORT AS directives.  */
 435   if (!info->relocatable)
 436     {
 437       Elf_Internal_Rela *            rel;
 438       Elf_Internal_Rela *            relend;
 439       Elf_Internal_Shdr *            symtab_hdr;
 440       struct elf_link_hash_entry **  sym_hashes;
 441       struct elf_link_hash_entry **  sym_hashes_end;
 442       struct elf_link_hash_table *   hash_table;
 443       symbol_rename *                ptr;
 444       bfd_size_type                  num_global_syms;
 445       unsigned long                  num_local_syms;
 446
 447       BFD_ASSERT (! elf_bad_symtab (input_bfd));
 448
 449       symtab_hdr       = & elf_tdata (input_bfd)->symtab_hdr;
 450       hash_table       = elf_hash_table (info);
 451       num_local_syms   = symtab_hdr->sh_info;
 452       num_global_syms  = symtab_hdr->sh_size / sizeof (Elf32_External_Sym);
 453       num_global_syms -= num_local_syms;
 454       sym_hashes       = elf_sym_hashes (input_bfd);
 455       sym_hashes_end   = sym_hashes + num_global_syms;
 456
 457       /* First scan the rename table, caching the hash entry and the new index.  */
 458       for (ptr = rename_list; ptr; ptr = ptr->next)
 459         {
 460           struct elf_link_hash_entry *   new_hash;
 461           struct elf_link_hash_entry **  h;
 462
 463           ptr->current_hash = elf_link_hash_lookup (hash_table, ptr->current_name, FALSE, FALSE, TRUE);
 464
 465           if (ptr->current_hash == NULL)
 466             {
 467               if (DEBUG)
 468                 fprintf (stderr, "IMPORT AS: current symbol '%s' does not exist\n", ptr->current_name);
 469               continue;
 470             }
 471
 472           new_hash = elf_link_hash_lookup (hash_table, ptr->new_name, FALSE, FALSE, TRUE);
 473
 474           /* If we could not find the symbol then it is a new, undefined symbol.
 475              Symbian want this behaviour - ie they want to be able to rename the
 476              reference in a reloc from one undefined symbol to another, new and
 477              undefined symbol.  So we create that symbol here.  */
 478           if (new_hash == NULL)
 479             {
 480               asection *                     psec = bfd_und_section_ptr;
 481               Elf_Internal_Sym               new_sym;
 482               bfd_vma                        new_value = 0;
 483               bfd_boolean                    skip;
 484               bfd_boolean                    override;
 485               bfd_boolean                    type_change_ok;
 486               bfd_boolean                    size_change_ok;
 487
 488               new_sym.st_value = 0;
 489               new_sym.st_size  = 0;
 490               new_sym.st_name  = -1;
 491               new_sym.st_info  = ELF_ST_INFO (STB_GLOBAL, STT_FUNC);
 492               new_sym.st_other = ELF_ST_VISIBILITY (STV_DEFAULT);
 493               new_sym.st_shndx = SHN_UNDEF;
 494
 495               if (! _bfd_elf_merge_symbol (input_bfd, info,
 496                                            ptr->new_name, & new_sym,
 497                                            & psec, & new_value, NULL,
 498                                            & new_hash, & skip,
 499                                            & override, & type_change_ok,
 500                                            & size_change_ok))
 501                 {
 502                   _bfd_error_handler (_("%B: Failed to add renamed symbol %s"),
 503                                       input_bfd, ptr->new_name);
 504                   continue;
 505                 }
 506               /* XXX - should we check psec, skip, override etc ?  */
 507
 508               new_hash->root.type = bfd_link_hash_undefined;
 509
 510               /* Allow the symbol to become local if necessary.  */
 511               if (new_hash->dynindx == -1)
 512                 new_hash->def_regular = 1;
 513
 514               if (DEBUG)
 515                 fprintf (stderr, "Created new symbol %s\n", ptr->new_name);
 516             }
 517
 518           /* Convert the new_hash value into a index into the table of symbol hashes.  */
 519           for (h = sym_hashes; h < sym_hashes_end; h ++)
 520             {
 521               if (* h == new_hash)
 522                 {
 523                   ptr->new_symndx = h - sym_hashes + num_local_syms;
 524                   if (DEBUG)
 525                     fprintf (stderr, "Converted new hash to index of %ld\n", ptr->new_symndx);
 526                   break;
 527                 }
 528             }
 529           /* If the new symbol is not in the hash table then it must be
 530              because it is one of the newly created undefined symbols
 531              manufactured above.  So we extend the sym has table here to
 532              include this extra symbol.  */
 533           if (h == sym_hashes_end)
 534             {
 535               struct elf_link_hash_entry **  new_sym_hashes;
 536
 537               /* This is not very efficient, but it works.  */
 538               ++ num_global_syms;
 539               new_sym_hashes = bfd_alloc (input_bfd, num_global_syms * sizeof * sym_hashes);
 540               if (new_sym_hashes == NULL)
 541                 {
 542                   if (DEBUG)
 543                     fprintf (stderr, "Out of memory extending hash table\n");
 544                   continue;
 545                 }
 546               memcpy (new_sym_hashes, sym_hashes, (num_global_syms - 1) * sizeof * sym_hashes);
 547               new_sym_hashes[num_global_syms - 1] = new_hash;
 548               elf_sym_hashes (input_bfd) = sym_hashes = new_sym_hashes;
 549               sym_hashes_end = sym_hashes + num_global_syms;
 550               symtab_hdr->sh_size  = (num_global_syms + num_local_syms) * sizeof (Elf32_External_Sym);
 551
 552               ptr->new_symndx = num_global_syms - 1 + num_local_syms;
 553
 554               if (DEBUG)
 555                 fprintf (stderr, "Extended symbol hash table to insert new symbol as index %ld\n",
 556                          ptr->new_symndx);
 557             }
 558         }
 559
 560       /* Walk the reloc list looking for references to renamed symbols.
 561          When we find one, we alter the index in the reloc to point to the new symbol.  */
 562       for (rel = relocs, relend = relocs + input_section->reloc_count;
 563            rel < relend;
 564            rel ++)
 565         {
 566           int                          r_type;
 567           unsigned long                r_symndx;
 568           struct elf_link_hash_entry * h;
 569
 570           r_symndx = ELF32_R_SYM (rel->r_info);
 571           r_type = ELF32_R_TYPE (rel->r_info);
 572
 573           /* Ignore unused relocs.  */
 574           if ((r_type >= (int) R_SH_GNU_VTINHERIT
 575                && r_type <= (int) R_SH_LABEL)
 576               || r_type == (int) R_SH_NONE
 577               || r_type < 0
 578               || r_type >= R_SH_max)
 579             continue;
 580
 581           /* Ignore relocs against local symbols.  */
 582           if (r_symndx < num_local_syms)
 583             continue;
 584
 585           BFD_ASSERT (r_symndx < (num_global_syms + num_local_syms));
 586           h = sym_hashes[r_symndx - num_local_syms];
 587           BFD_ASSERT (h != NULL);
 588
 589           while (   h->root.type == bfd_link_hash_indirect
 590                  || h->root.type == bfd_link_hash_warning)
 591             h = (struct elf_link_hash_entry *) h->root.u.i.link;
 592
 593           /* If the symbol is defined there is no need to rename it.
 594              XXX - is this true ?  */
 595           if (   h->root.type == bfd_link_hash_defined
 596               || h->root.type == bfd_link_hash_defweak
 597               || h->root.type == bfd_link_hash_undefweak)
 598             continue;
 599
 600           for (ptr = rename_list; ptr; ptr = ptr->next)
 601             if (h == ptr->current_hash)
 602               {
 603                 BFD_ASSERT (ptr->new_symndx);
 604                 if (DEBUG)
 605                   fprintf (stderr, "convert reloc %lx from using index %ld to using index %ld\n",
 606                            (long) rel->r_info, (long) ELF32_R_SYM (rel->r_info), ptr->new_symndx);
 607                 rel->r_info = ELF32_R_INFO (ptr->new_symndx, r_type);
 608                 break;
 609               }
 610         }
 611     }
 612
 613   return sh_elf_relocate_section (output_bfd, info, input_bfd, input_section,
 614                                   contents, relocs, local_syms, local_sections);
 615 }
 616
 617 static bfd_boolean
 618 sh_symbian_check_directives (bfd *abfd, struct bfd_link_info *info)
 619 {
 620   return bfd_elf32_sh_symbian_process_directives (info, abfd);
 621 }
 622
 623 #define TARGET_LITTLE_SYM       bfd_elf32_shl_symbian_vec
 624 #define TARGET_LITTLE_NAME      "elf32-shl-symbian"
 625
 626 #undef  elf_backend_relocate_section
 627 #define elf_backend_relocate_section    sh_symbian_relocate_section
 628 #undef  elf_backend_check_directives
 629 #define elf_backend_check_directives    sh_symbian_check_directives
 630
 631 #include "elf32-target.h"